Aryl-Fluoride Bond-Forming Reductive Elimination from Nickel(IV) Centers

The treatment of pyridine- and pyrazole-ligated Ni-II sigma-aryl complexes with Selectfluor results in C(sp(2))-F bond formation under mild conditions. With appropriate design of supporting ligands, diamagnetic Ni-IV sigma-aryl fluoride intermediates can be detected spectroscopically and/or isolated during these transformations. These studies demonstrate for the first time that Ni-IV sigma-aryl fluoride complexes participate in challenging C(sp(2))-F bond-forming reductive elimination to yield aryl fluoride products.